Despite being a simple fact of life, the majority of women still know very little about periods. So, at a time when big brands like Bodyform are taking a stand to banish some of the taboos that still surround menstruation (check out their #bloodnormal campaign), we decided to do some of our own myth-busting.

Here, we team up with Anna Druet, science researcher at Women's health app Clue, to talk about one of the most common yet least talked-about subjects when it comes to periods: heavy bleeding. Or, to be more specific, menstrual blood clots. Never heard of them either? Read on to find out more…

What are menstrual blood clots?

Menstrual blood clots can appear during the heavier days of your period, and as such, are completely normal. Anna says:

"The period happens when the body sheds the uterine lining, which can vary in flow – from light on some days, to heavy on others. Menstrual blood clots typically happen at times when the flow increases in speed and volume, but are a normal part of the period. The clots are exactly the same as the blood you lose on other days, which over the period typically adds up to 2-3 tablespoons."

So, where do they come from? Well, blood clots happen as a result of coagulation, which changes the blood from a liquid to a semi-solid state.

"During the period, the body produces anticoagulants, which are meant to prevent your blood from clotting. It's thought that when the flow is at its heaviest, they often don't have enough time to work, which results in blood clots."

Should you ever worry about menstrual blood clots?

Typically, menstrual blood clots aren't a problem – especially if they occur during the heaviest days of your period. However, if you are experiencing multiple blood clots that are larger than a 10 pence piece, then you might be experiencing HMB (heavy menstrual bleeding). Anna says:

"While this isn't life threatening, HMB can be tiring and disruptive for your daily life. If you think this might be the case, make an appointment with your GP to discuss the symptoms."

In some instances, HMB can also cause iron deficiency – often resulting in tiredness and dizziness.

"You yourself can't do anything to control menstrual blood clots, but if you speak to your GP, they might be able to help. If your GP agrees that you are suffering from HMB, they should investigate the reason behind your heavy menstrual bleeding, and address that whenever possible. In some situations they may prescribe hormonal contraception, to make bleeding lighter."

Signs your period is considered 'heavy'...

You bleed for more than 8-10 days, and this is repeated every month.

Bleeding makes it difficult for you to go about your normal day-to-day life, like going to work or attending social events.

You are anaemic.

You often notice menstrual clots during your period.

You experience 'flooding'– a term describing the sudden onset of periods.

In younger women, heavy periods can often be attributed to a temporary hormone imbalance, which corrects itself over time.